Budget Bicycling - 2009 Journal
15 March 2009
Once again I've left the chain replacement too late and worn the sprockets out. The new chain was $13 from K-Mart, and the sprockets were off the first loose wheel I found in the background with a Shimano-splined freewheel still attached. It's only a 5-speed, but it has the same spread of ratios as the 6-speed it replaces (28-24-20-17-14 Vs 28-24-21-18-16-14).
A nice new chain over a nice old freewheel (obviously the bike is upside-down!)
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My favourite gears (2nd, 3rd & 4th) are very worn, leaving 1st, 5th and 6th in pretty good shape.
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I just have to find a couple of tiny punctures and these 6 bikes will be ready to go onto the bikes for sale list.
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16 March 2009
I found the new freewheel made my journey to work much easier (probably a lot less chain friction), so I thought I should finally act like a "serious" cyclist and do some gear charts. The yellow backgrounds indicate the gear ratios that I use.
Gear Ratios
| |
28t |
24t |
20t |
17t |
14t |
| 28t |
1.0 |
1.2 |
1.4 |
1.6 |
2.0 |
| 38t |
1.4 |
1.6 |
1.9 |
2.2 |
2.7 |
| 48t |
1.7 |
2.0 |
2.4 |
2.8 |
3.4 |
Here's the same table in gear-inches, to be really hardcore.
Gear Inches
| |
28t |
24t |
20t |
17t |
14t |
| 28t |
26.0 |
30.3 |
36.4 |
42.8 |
52.0 |
| 38t |
35.3 |
41.2 |
49.4 |
58.1 |
70.6 |
| 48t |
44.6 |
52.0 |
62.4 |
73.4 |
89.1 |
My usual cadence is between 60-80rpm or so (I don't have a cadence meter, so I'm just guessing using the "one thousand and one, one thousand and two..." method). Taking the middle ground on that, here's my road speed for each ratio at 70rpm:
km/h @ 70rpm
| |
28t |
24t |
20t |
17t |
14t |
| 28t |
8.7 |
10.2 |
12.2 |
14.3 |
17.4 |
| 38t |
11.8 |
13.8 |
16.5 |
19.5 |
23.6 |
| 48t |
14.9 |
17.4 |
20.9 |
24.6 |
29.9 |
20 April 2009
I must be getting close to the record - I've got 24 patches on Aaargh's rear tube now. Yesterday's puncture was a slow leak caused by a sliver of glass, that just happened to go straight through the middle of a pre-existing patch (the odds of that happening are getting better and better with that many patches on the tube, after all).
If it ever happens to you, old patches are fairly easily removed simply by heating them up with a match or cigarette lighter flame for a few seconds, then peeling them off once the glue softens.
Today's puncture happened this morning about 300m short of my destination, when I had a 2" nail go through the tyre and puncture the tube in 2 places. Interestingly enough it was the head of the nail that went into the tyre, leaving the pointy end sticking out.
If all goes well I should achieve 10,000km on Thursday. I'll keep riding Aaargh after that point, but I won't be updating the ride log any more. I think that my point has been adequately proven. ;-)
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